Barometer for use in connection with diagnostic work



D. R. BARR.

June 23, 1 931.

BAROMETER FOR USE IN CONNECTION WITH DIAGNOSTIC WORK Filed April 25,1928 INVENTOR ATTORNEY Patented June 23, 1931 UNITED STATES DANIEL B.BARR, OF GRAND RAPIDS, OHIO,

PATENT OFFICE ASS IGNOR TO TAYLOR INSTRUMENT COM- PANIES, OF ROCHESTER,NEW YORK, A CORPORATION OF YORK BABOMETER ron USE IN connnc'rron wi'rnDIAGNOSTIC worn:

Application filed April 25,

'5 is necessary to reduce volumes of air at an observed pressure and anobserved temperature to the corresponding volumes at standardconditions, usually C. (temp), 760 mm. (pressure) and 80% aqueous vaporsaturation.

It is common practice to provide tables for facilitating the reductionof observed values of volumes at observed conditions of pressure andtemperature to standard conditions.

The resent invention has for its object to simplii y not only the use ofthe table, butalso the observations to be made.

Another object is a barometer which aside from its usual pressure scalecontains indicia and mechanism for translating the pressure indicatedtogether with other values observed into terms of standard conditions.

For a full explanation of the invention, reference is made to thedrawings, wherein:

Fi 1 is a face view of a barometer embodyin t e invention;

Tig. 2 is an enlarged view of a part thereof and Fig. 3 is a similarview, on a smaller scale, of another form of the invention.

The barometer mechanism may be of any well known construction enclosedin the casing 1 and including a pointer 2 co-operating with a scale 5graduated to indicate atmospheric pressure.

For the purpose of the invention, in agreement with the medical practicein this respect, the pressure is indicated in millimeters of mercury.

The pressure is marked along the periphery of the dial 3, as indicatedby the numbers 640, 645, 650 and 655 780.

Inradial alignment with each number is a column of figures.concentrically with the arbor of the instrument, but independently ofit, preferably on the glass cover, is mounted a hand 4, which may beturned by means of a knurled nut 4a or the like to any desired positionon the dial. On the hand 4 are marked in superposition numbers consecu-1928." Serial No. 272,686.

tively varying from about 1537. Thereare as many numbers on this hand asthere are figuresin each of the radial rows in'alignment with thepressure indications. In the particular instance, there are twelvenumbers on the hand-and twelve numbers in each radial row on the dial.

The numbers in-the radial columns on the dial signify numbers ofcalories per liter 'of oxygen. One liter. of oxygen at 0? C. and 760 mm.pressure is assumed, when inhaled, to

have a calorific value of 4.85 cal. -The physician calculates the volumeof oxygen inhaled per hour and he must 'multiply'this volume, expressedin liters, by a factor corresponding to thefactor 4.85. This factor,however, is ordinarily smaller than 485 since the barometric pressure ataltitudes higher than" sea level is usually lower than 760 mm. andthet'emperature is usually higher'th'an ;0. The numbers in the radialcolumns on the dial represent the calorificvalues of 1,.liter of oxygenat different temperatures and different barometric'pressures. Eachnumber represents thecalorific value a liter of oxygen at" a definitetemperature and a definite barometric pressure would have at 0 C. and760 mm. pressure. The definite temperature referred tois that number onthe hand 4, which lies on the same circle asthe number in question andthe definite pressure is the pressure indication on the scale radiallyoutwardly fr'om'the'column containing the number in question." Eachnumber represents the calorific value of 1 liter of oxygen'measured at aknown temperature and known pressure, when'reduced to standardconditions; 7

The'operation and significance ofthe arrangement are as follows:

Thephysician'or otheroperator moves the hand 4 into alignment with thepointer 2' or rather into juxtapositionof the radial row nearest to thepointer and notes the-nuinber in lateral alignment with a selected oneofthe numbers on the hand 4. 1 These numbers denote temperatures 'ofrespiratory contents in a spirometer chamber which does not form a partof this invention. The operator, at the time of operating the hand 4,consults the thermometer usually attached to the spirometer and thenmakes the reading on the dial 3, as mentioned. Assume that thetemperature is 19 and the pointer stands at 699 as indicated in Fig. 2.The hand 4 is moved to the position indicated so that the numbers on thehand are. directly adjacent to the numbers in the radial row inalignment With the pressure indication 700. The number 43.08 is thenumber adjacent to the number 19 on the hand 4 and thisnumber 1.08 isthe number sought.

In the particular instance, the calorific equivalent of one liter ofoxygen at 19 (3., 700 min. pressure and anyrelative humidity combinedwith factors for reduction of vol nine to 0 C. 111111., 760 mm. pressureand aqueous vapor saturation.

Itis understood that the figures of the radial roWs represent, ingeneral, correction factors including the reduction of the volumeofoxygen at any observed pressure and temperature to the volumecorresponding to standard conditions of pressure and. temperature.

The handd is preferably of transparent material such as celluloid tofacilitate visual juxtaposition of the numbers on the hand and thenumbers on the dial.

In Fig. 3, the dial is the same as in Fig. 1, but in placeof the hand 4,a disk 6 is mounted for pivotalmovement. The disk 6 is provided With aslit 7 on one or both sides of which are marked the numbers 15-37.

I claim:

1. In a barometric device, the combination with a pointer, of a dial forthe pointer having along its periphery a set of barometric pressureindications corresponding to different positions of the pointer andhaving inwardly of each of said pressure indications a radial group ofdiagnostic indicia, a member pivotally mounted concentrically With thepointer and the dial and bearing temperature indicia in radial alignmentfor correlation with the said diagnostic indica, and means for movingthe said member and the dial relatively to one another.

2. In a barometric device, the combination with a pointer, of a dial forthe pointer hav ing along its periphery a set of barometric pressureindications corresponding to different positions of the pointer andhaving inwardly of each pressure indication a radial group of diagnosticindicia, a hand pivotally mounted concentrically with the pointer andthe dial and bearing temperature indicia in radial alignment forcorrelation with the said diagnoistic indicia, and means for moving thehand about its pivot.

In testimonywhereof I afiix my signature.

DANIEL R. BARR.

